1st Avenue & I-80 Interchange

Coralville Diverging Diamond interchange rendering

Diverging Diamond Interchange
The Iowa Department of Transportation plans to reconstruct the interchange at I-80 exit 242 and 1st Avenue with a diverging diamond interchange (DDI). The Iowa DOT is the lead agency on this project.

Updates: Current & Upcoming Work
Major construction started in mid-March and reduces 1st Avenue to one lane in each direction over I-80 into fall 2024. Drivers should anticipate traffic delays and plan accordingly.

On 1st Avenue:
Between 9th Street and Holiday Road: 

  • March 20, 2023 through April 21, 2023*: 
    • Northbound and southbound traffic shifts to the west side of 1st Avenue across I-80 and is one lane in each direction (head-to-head) through late 2024.
    • Northbound traffic on 1st Avenue that wants to head eastbound on I-80 needs to enter the right turn lane just north of the E. 9th Street intersection.  
    • All turns to and from the I-80 ramps will be open at all times. (See image below).

On I-80 eastbound (Exit 242)*: 

  • March 27-30, 2023 : Eastbound I-80 will be closed at 1st Avenue to remove the south half of the existing northbound 1st Avenue bridge.  Eastbound I-80 traffic will be detoured off I-80 (exit 242) onto the exit ramp and then continue straight onto the entrance ramp to get back onto eastbound I-80.  The closure / detour will begin each night at 11:00 pm and run through 5:00 am the next morning.  
  • March 6, 2023-December 31, 2023: Intermittent lane closures overnight between 7:00 pm and 6:00 am Monday through Thursday, and between 9:00 pm and 6:00 am Sunday.

On I-80 westbound (Exit 242):

  • April 3-6, 2023: Westbound I-80 will be closed at 1st Avenue to remove the north half of the existing northbound 1st Avenue bridge. Westbound I-80 traffic will be detoured off I-80 (exit 242) onto the exit ramp and then continue straight onto the entrance ramp to get back onto westbound I-80. The closure / detour will begin each night at 11:00 pm and run through 5:00 am the next morning.
  • March 6, 2023-December 31, 2023*: Intermittent lane closures overnight between 7:00 pm and 6:00 am Monday through Thursday, and between 9:00 pm and 6:00 am Sunday.

*(Dates subject to change based on weather and unforeseen circumstances)

Comment: Davenport RCE (800-262-5145) 

Please check 511ia.org for the latest updates to the project.

Contact Us

  1. Iowa Department of Transportation

    Catherine Cutler
    Transportation Planner
    Email

    Iowa DOT logo


    City of Coralville

    Scott Larson
    City Engineer 
    Email

    1512 7th St.
    P.O. Box 5127
    Coralville, IA  52241

    Ph: 319.248.1720
    Fx: 319.248.1894
    Staff Directory

Traffic patterns starting March 20, 2023

1stAve80DDI_Phase2_Stage1_03082023

Project at a Glance

The existing interchange at I-80 exit 242 is the original configuration constructed in the 1960s when I-80 was built through Iowa. The new diverging diamond interchange will provide safety improvements and is designed to handle projected traffic volumes. 

Major construction began in mid-March 2023, and reduces 1st Avenue to one lane in each direction over I-80. 1st Avenue will remain one lane in each direction over I-80 into fall 2024.

The prime contractor is Peterson Contractors, Inc., of Reinbeck, Iowa. The Iowa DOT is administering and inspecting the project.

Highlights Once Complete

  • Diverging diamond interchange design eliminates the left turn phase at signalized intersections. This reduces overall traffic delay while also providing a significant safety improvement since left-turning traffic is no longer crossing opposing traffic lanes.
  • New grade-separated trail with underpasses and a trail bridge over I-80.
  • New 1st Avenue bridges accommodate the potential future widening of I-80.
  • New, signalized intersection to serve Iowa River Landing Place and the Magellan Terminal. 
  • New stormwater management practices, traffic signals, roadway lighting, and aesthetic treatments. 

  1. Traffic & Pedestrian Impact
  2. Timeline
  3. Cost

Traffic & Pedestrian Impact

  • The project will utilize staged construction, including temporary pavement and temporary traffic signals. 
  • One lane of traffic will be maintained in each direction on 1st Avenue at all times.  
  •  Drivers should anticipate traffic delays and plan accordingly. 
  • After the 1st Avenue Trail closures in October and November 2022, pedestrian access along 1st Avenue over I-80 should not be impacted again for the remainder of the project.

Learn More
Iowa Department of Transportation
Iowa DOT project website

Watch Video: Navigating the Diverging Diamond Interchange
 

Stay Informed


  1. 1st Ave & I-80 Interchange Project: Demolition of Existing Northbound 1st Ave Bridge over I-80

    Demo of the existing northbound 1st Ave bridge over I-80 will occur overnight when I-80 traffic volume is low; I-80 traffic will detour around the work zone using the exit and entrance ramps at 1st Ave. Read on...
  2. 1st Avenue & I-80 Interchange (Exit 242) Construction

    Major construction begins March 20 to reconstruct the 1st Ave. and I-80 interchange (Exit 242) into a diverging diamond interchange. Traffic delays are expected; plan accordingly. Read on...
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